Not really a complete answer to your question but: Beethoven had originally dedicated his Eroica symphony to Napoleon and called it the Bonaparte symphony. When he heard that Napoleon had crowned himself Emperor, he raged and claimed that Napoleon would now become a tyrant, and tore up the manuscript title paper. Here is a picture of another copy with "Napoleon" scratched out. So it did affect at least a couple aspects of his music - heroism was a very prominent theme in Beethoven's life, recurring in many pieces like the Emperor concerto and also in his sole opera, Fidelio. He viewed Napoleon as a hero, and his disillusionment was pretty profound at that point, although he seemed to soften his stance toward Napoleon somewhat later on, adding "In memory of a great man" to the Eroica's dedication.